The inventive concepts relate to image sensors, and more particularly, to image sensors having an optical black sensor area.
Image sensors having improved performance are being used in various fields, such as digital cameras, camcorders, mobile phones, personal communication systems (PCSs), game players, surveillance cameras, and medical micro-cameras. Image sensors can convert an optical image signal into an electrical image signal. An image sensor may include an active pixel sensor area for receiving incident light and converting the light into an electrical signal and an optical black sensor area for blocking inflow of light and providing a reference of a black signal to the active pixel sensor area. In the manufacturing of the image sensor, when a relatively big step difference exists between the active pixel sensor area and the optical black sensor area while a color filter layer is being formed, thicknesses of color filters adjacent to the optical black sensor area from among a plurality of color filters formed on the active pixel sensor area may be non-uniform due to the step difference. Consequently, problems such as distortion of an image signal or degradation of the color may occur in a portion of the active pixel sensor area that is adjacent to the optical black sensor area.